Selma , Alabama -LRB- CNN -RRB- Crowds massed at a bridge in Selma , Alabama , Sunday to remember and reflect upon the sacrifices of another crowd that gathered at the same bridge half a century ago on a day that came to be known as `` Bloody Sunday . ''

Walkers marched across the Edmund Pettus Bridge in the afternoon to commemorate those freedom-marchers who were clubbed and tear-gassed by state troopers as they peacefully filed across on March 7 , 1965 . The crowd was massive . It was shoulder to shoulder near the bridge and several blocks away . There were so many people that walking is a bit misleading -- people just really moved inch by inch along the way .

The protest decades ago against the denial of civil rights to Americans based solely on the color of their skin , and the television coverage of the bludgeoning dealt them , hastened the passage of the Voting Rights Act of 1965 .

On Sunday at Selma 's Brown Chapel AME , a historically black church , leaders in the religious and political realm as well as community organizers gathered to hear speeches , sing hymns and remember what happened 50 years ago . U.S. Attorney General Eric Holder was in the audience . Rev. Jesse Jackson spoke , as did Rev. Al Sharpton .

An important figure in the decades-long fight for civil rights , former Atlanta Mayor and U.N. Ambassador Andrew Young remembered the struggle in the 1960s but wanted everyone to keep pushing forward and thinking about achieving economic equality today .

`` We 've got to focus on ourselves not as problems but as visionaries , '' he said .

`` We have come a long , long way , but I have enjoyed every bit of it , '' Young remarked .

Several people remarked at how much it meant that the day before , on Saturday , America 's first African-American President , Barack Obama , made a rousing speech on racial progress in a diverse country .

He said that the struggle against discrimination continues today . Looking back , the `` Bloody Sunday '' march was triggered when a law officer shot a black man dead the month before .

But it was about more -- the right to vote for all Americans . About 600 people were going to march 50 miles to the state capital in Montgomery before they were forcibly stopped .

Sunday 's festivities started with a breakfast and end late with a dance . A string of parades , receptions , reflections , films and discussions will fill the time in between . The commemoration marking 50 years since `` Bloody Sunday '' continues on Monday .

`` Our march is not yet finished . But we are getting closer , '' Obama said Saturday , his words echoing into a crowd of thousands lined up in front of him .

Obama emphasized that a day of commemoration is not enough to repay the debt paid by the marchers who were beaten 50 years ago as they demonstrated for voting rights .

`` If Selma taught us anything , it 's that our work is never done , '' the President said near Edmund Pettus Bridge .

Read President Obama 's prepared remarks

The President said that what civil rights marchers did years ago `` will reverberate through the ages . Not because the change they won was preordained ; not because their victory was complete ; but because they proved that nonviolent change is possible ; that love and hope can conquer hate . ''

He hailed the marchers as heroes .

The President said that `` the Americans who crossed this bridge , they were not physically imposing , but they gave courage to millions . They held no elected office . But they led a nation . ''

The President called on Congress to restore the Voting Rights Act , first passed in 1965 .

In 2013 , the U.S. Supreme Court overturned a key provision of the law that required certain states with a history of racial discrimination at the polls to `` pre-clear '' any changes to the law with the federal government before implementing them .

Efforts to revive key provisions of the act have stalled in Congress .

50 years later : Memories from ` Bloody Sunday ' nurse

Many of the nation 's leaders , activists and celebrities were in Selma on Saturday attending various activities taking place in memory of the historic event .

On Saturday , Rep. John Lewis -- one of the demonstrators bloodied by troopers 50 years ago -- and nearly 100 other members of Congress from both parties joined the President at the bridge in Selma -- a bridge that still bears the name of Pettus , a Confederate general who was also a Ku Klux Klan leader .

`` We must use this moment to recommit ourselves to do all we can to finish this work . There 's still work to be done , '' said Lewis , adding this is an opportunity to `` redeem the soul of America . ''

John Lewis 's memories of the march

Reflecting a sense of change in the half century since `` Bloody Sunday , '' and with Selma again in a national media spotlight , the mood in the crowd Saturday was of unity , and talks were focused on how to move America forward .

But some current Selma residents worried that after the dignitaries leave their town -- with a population 82 % black and with more than 40 % of its people living below the national poverty level -- will fade from view except for its historical significance .

Geraldine Martin , 59 , has lived in Selma all her life . She was 9 years old on `` Bloody Sunday '' and with her mother had just welcomed a little sister , Belinda , to the world on that day . The two sisters grew up in Selma less than a decade apart .

Opinion : Selma 's historic bridge deserves a better name

Belinda left Selma after high school and now lives in Atlanta . Her view of Selma has changed over the years -- looking in from the outside .

`` I do n't see how Selma will move forward without togetherness , '' said Belinda . `` There is no diversity in Selma . People do n't live together . ''

CNN 's Moni Basu reported from Selma . CNN 's Slma Shelbayah wrote and reported from Atlanta . CNN 's Steve Almasy and Douglas Brinkley contributed to this report .

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A large crowd walks the footsteps of those who marched 50 years ago

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They are crossing the Edmund Pettus Bridge , named for a former KKK leader

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President Obama called Saturday for renewal of Voting Rights Act